The present invention pertains to a method and apparatus for continuously monitoring and telemetering the momentary engine-side operating condition of a motor vehicle with respect to the vacuum created in the intake manifold of the engine, as output and reference quantities.
In addition to the general conventional vacuum-indicating devices of a variety of systems and for a variety of applications -- as described, for example, in German Pat. No. 82,836 -- there have been offered on the market so-called vacuum meters as dashboard accessory equipment for sport motor vehicles, based on the long-established finding that an engine runs at its optimum rpm or performance range whenever the vacuum in the intake manifold of the engine is highest.
All of these known devices, however, have not become popular with the majority of motor vehicle operators because, on the one hand, it is difficult to accommodate them on the dashboard and, on the other hand, they would have made some sense only if observation of the continually swinging needles would not distract the driver from the road traffic so much. Another disadvantage is that, for one thing, in all known devices the complicated transmission mechanisms from the vacuum box or spring to the pendulum needle causes considerable inaccuracy of the measured values and, for another, the vacuum indication, as such, gives clear information so as to initiate action only to the technically-well-versed operator, but not the average driver.